Gateways serve as interface between different types of networks and provide a network transition. One example for a gateway is a VoIP gateway which provides a network transition between an IP-based, packet-oriented communication network, for example the Internet or an NGN (Next Generation Network), and a circuit-switched communication network, for example a fixed telecommunications network such as the ISDN.
Another example for a gateway is a so-called mobile radio gateway, which provides an interface between one or more mobile radio telecommunications networks and any other networks, for example a fixed telecommunications network or an IP network. A mobile radio gateway is called by the user of another network and via a mobile radio channel routes the desired connection into the mobile radio network in which the called subscriber is located. For this purpose, the mobile radio gateway implements the functionality of a mobile radio telephone and calls the called subscriber as a mobile radio telephone, so to speak. Mobile radio gateways thus have the same mobile radio modules as they are used in mobile radio terminals (Handys). Such mobile radio gateways are known for example from DE 103 14 144 A1.
It is known that the mobile radio gateway contains a multitude of plug-in cards, in particular so-called SIM cards for the mobile radio channels managed. Any kind of SIM-Karten of various network operators can be used. A SIM card is a plug-in card with an identifier by means of which a mobile radio device is assigned to a specific network operator, receives a particular telephone number and can unambiguously be identified in all mobile radio networks. In addition, a SIM card has a PIN number (PIN—Personal Identity Number), safety-relevant data such as communication keys and safety algorithms, user-specific data such as speed-dial numbers and network-specific data such as the identifier of the current location area. A SIM card personalizes a mobile radio terminal with regard to the user and with regard to the network operator and provides for the accounting of call charges of the network operator.
It is furthermore known that for the case that problems arise when establishing a communication connection, for example because the called end subscriber does not exist, the network is overloaded or a monetary credit volume of the calling subscriber is used up, a communication network generates a standardized voice message which is transmitted to the calling subscriber of a desired communication connection for information purposes. Examples for such standardized voice message include “subscriber not reachable”, “telephone number has changed” or “no more credit available”. In general, such standardized voice message is generated by a computer system or has been recorded in advance.
It is the object underlying the present invention to provide a method for using voice messages in telecommunications connections. Furthermore, a gateway should be provided for performing such method.